plating, anodizing, & finishing Q&As since 1989
Maximum safe watt density for zinc plating solution heating
May 8, 2022
Q. Good day
I would like to know what is the maximum safe watt density for heating elements used in alkaline zinc plating tanks.
The main worry I have is what effect the very high temperature at the surface of the heating element will have on the brightener and what limit the watt density is safe to be.
- Perth, Western Australia
A. Hi Boris. Sorry, I can't answer your question, and I hope someone else can.
But based on my experience as "the plating shop guy" for a firm which helped the major insurance carriers investigate fire insurance claims, I can warn you that electric heaters in polypropylene plating tanks are far-&-away the biggest cause of plating shop fires (an unmonitored solution level drop through evaporation, tank leak, or inadvertent pump-out allows the heater to radiate directly on the plastic and ignite it).
Even with careful double safeties, I don't think you should increase the watt density beyond what is currently accepted practice.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey